How the portrait effect works
Large camera sensors and wide apertures blur the background optically (shallow depth of field). Phones simulate this: software detects the subject, keeps it sharp and blurs the rest. An AI background tool does the same on an existing photo.
Step by step
- Open Blur background and add your photo.
- The subject is detected and the background is replaced with a blurred copy of the original.
- Adjust the Blur slider: subtle values look natural for portraits, strong values isolate products.
- Use Refine to restore any part of the subject that got blurred, such as a hand or hair.
Tips for a natural look
- Moderate blur looks more believable than extreme blur, especially when the background is close to the subject.
- Photos with clear separation between subject and background give the cleanest edges.
- Keep the subject’s edges soft — a hard cut edge next to a heavy blur looks artificial.
Blur or remove?
Blurring keeps the atmosphere of a place. If the background is ugly or irrelevant, it may be better to change it to a colour or gradient, or to remove it completely.
Frequently asked questions
Can I blur the background of an old photo?
Yes. The tool works on any image, regardless of the camera that took it.
Will the subject stay at full resolution?
Yes, the subject stays sharp; only the background is blurred.